Piston



July 21, 1931.

A. B. RAYMOND PISTON Filed Oct. 17, 1 928 llv f M J 5&5.

3 t firm/1? B. EW/w/w or attorney Patented Jul 21, 1931 ARTHUR B. nAYMoNn, on MoN'rcLeIn; ivEwJnnsEY- manta Application filed October 17,1 5. fs riaiino. 313,064. v i

' My present invention relatesto an improved piston of the reciprocating type for use in internal combustion engines. "While the p1s-fl' In carrying out my'nvention I utilize a hollow piston that iscomparatively light in weight; is so shaped as to permit the free and unobstructed entrance of the fuel charge to thec'hamber above the piston and cause an I increased velocity of'the fuelmixture as it is charged into the chamber. Means are also provided whereby' the exhaust gases may be expelled from the cylinder in such manner as to practically clear the cylinder. of these gases. In the structure of the piston means are provided wherebyan even expansion under the head from combustion, is insured without; distorting the piston, and thus a smooth reciprocating movement of thepiston is accomplished. I The invention f consists in certain novel combinations and arrangements of parts as willhereinafter be more'fully set forth and olaimed."' 'f Y In the accompanying drawings I have illustrated one complete example of the physical embodiment of my invention wherein the parts are combined and arranged according to the best mode I have so far devised for the practical application of the principles of myinvention. v y p 40 Figure 1 is a top plan view of apiston involving my invention,showing by dotted lines and arrows the movementof the fresh fuel charge, and themovement of the exhaust gases to the exhaust port of the cylinder. 7

Fig. 2 is a side view at the top. of the piston as seen from the right in Fig; 1. I

.'Fig. 3 is a sectional detail view at line '33 of Fig. 1. p p I u y Fig. 4 is a sectional detail view at line el-4 of Fig. 1.

the piston is fashioned with diametrically The, piston is ofthe usual -hollow,'cylindri- I I cal shapeand is preferably, fashioned from lynite; "aluminum, or' other similar material, With-its'Skirt' open at the lower end" and opposed openings 2, 2 in its wall forusesin assembling the piston pin and" connecting rod, not shown,

The body 3 of the piston is fashioned with a; plurality" of annular, "exterior; grooves 4, for the; reception and "retention of 'piston rings, all of whichtare located above the pis ton pin'which is journalled in a pair of spaced transversely, extending bearing bosses or sleeves 5 and 6. These"bosses are integral with apair'of'webs ;7 and 8 that depend from the head of thepiston', and the parallelw'eb's are joine'd by a' transversely extending cross web 9' in the form of an arch. The webs are disposed transversely of the longitudinal a'xesbf the two bosses and the bosses' are axially-alined with the ope'nin'gs fZ, 2 and; ac-

cessible means are. thus providedfor con-1' trolling the end play-of the piston pin in the bosses Without necessity of using, set screws. orother devices. Y r

f noted that the outeredges of the bosses are free from the skirt of the piston,

andlithatthe'inner edges of the'bossesare spaced equidistantfrom the'axial center of i the piston, thus connecting the bossessolely' I withthe headof the piston. j ii I The Webs 7 and'8, as seen in Fig l, decrease in width or taperffromthe head 10' of the piston'to the respective bosses, and the cross web 9. is arched between the two bosses 7 and i 8, thus employing a minimum amount of material'to secure amaximum bracing effect and strength in the interior of the piston structure.

Because of this arrangement in the interior I structure of the hollow piston, the skirt of the piston is permitted to expand evenly and um'- formly throughout its cylindrical or circumferential area and the bosses and webs that are free from the body of the piston receive a ma or portion of their heat with consequent expansion directly from the head of the piston from which they are supported.

The d 10 of the piston is fashioned with 7 Y I a pointed dome 11, the apex 12 of the dome being located centrally of the piston and a recess 13 is formed in theclome, which, as seen in Fig. 1 in horizontal position is of V- shape, The perpendicular fiat walls of the recess .(Fig. a) merge into grooves 14 with the t head p ti n. 10 f the piston...

, e"; exhaust, gasesare expelled-1 on. h scavenging stroke of the piston, as indicated by the arrows between the letters E, E the fresh fuel charge spreadingout in m'ushroomi fashion to assist in forcing the gases of com bustion to the exhaust port. Upon reference i to Fig.1 it will beseenrthatt the fresh fuel charge from the intake port; of the cylinder,

7 as indieated between the-twoline L11 enters the iee ss; through an arc of approximate 1y Z8J1egrees, whilethe I gases of combustion are-expelled; fromzthe space. abovet e; piston i l through a larger exhaust nertlbetween the lines. E E of. approximately 146- degrees flhere essslitiafio sa free and unobstructthe" engine. r

' Lett rstPatent ifs-z.-

ed entrance of the fuel chargessf omthe in,

takeportgthe cleme of the-pis .e 1- bafies t charge and the; con tricted form iom of; the reeessine eases; theelocity of the. incominguel charge, Whieh7 at the center of the cempr seieni chamber: is defleetecl p ardly by: he ells at the re ss-r Ihe i ture; as it .thr ughrthe ce ter-o the cylinderthen spreads outward yin a flaring formation o seavengel he uppen'por ien f'the ey indelz and;isein;bestzp'e sibleeendition fer'comp ese 7 $10.11: eembustion du ng' he eperetioh; of-

deseribed' my inment-i.err;

- fu ly and desiretose ure; by:

What-,lclaim: as'new- A. pisten; a defi e-shaped head-L therefer;

1 anda -shapedrecese insaidrheadhaving-its apex coincident with the apex. ofithe head and termina ing in. a defl cting fa e-etthe apexae the recession turning the fueleharge alengthe axial line of? thepist n where y a fr sh; fue -eharge i bafii l; elocity nerea ed; v '7 2. A iston having: en itsheaigaidewalls e11: eang zerging lines; fer 2onstrn ting a fresh fuel charge asiit flows; towardi thecenter of the p ston and; guiding means or upwardlyiefiec ing he constricted charge along the EB B1 Ramona 

